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<h4 class="subsection">4.2.4 Else</h4>

<a name="index-_0023else"></a>
<p>The &lsquo;<samp>#else</samp>&rsquo; directive can be added to a conditional to provide
alternative text to be used if the condition fails.  This is what it
looks like:
</p>
<div class="smallexample">
<pre class="smallexample">#if <var>expression</var>
<var>text-if-true</var>
#else /* Not <var>expression</var> */
<var>text-if-false</var>
#endif /* Not <var>expression</var> */
</pre></div>

<p>If <var>expression</var> is nonzero, the <var>text-if-true</var> is included and
the <var>text-if-false</var> is skipped.  If <var>expression</var> is zero, the
opposite happens.
</p>
<p>You can use &lsquo;<samp>#else</samp>&rsquo; with &lsquo;<samp>#ifdef</samp>&rsquo; and &lsquo;<samp>#ifndef</samp>&rsquo;, too.
</p>



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